Diabetes mellitus effects on the ocular surface epithelium have been shown to include the need for removal of epithelium at the time of vitreous surgery, post- vitrectomy epithelial defects, decreased corneal sensitivity in humans and delayed healing in rats, with some evidence in humans and rats, that the sorbitol pathway may be involved in the abnormalities seen in cornea as it is in lens, neural and other tissues. We propose to study diabetic effects on the corneal and conjunctival epithelium by (1) biochemical analysis of diabetic tissue including (a) measurements of sorbital pathway intermediates, and (b) studies of basement membrane composition; (2) functional studies of the effect of diabetes on epithelial healing in humans, and (3) determination of the effects of aldose reductase inhibitors on human corneal epithelial healing.